[en] Electromagnetic calorimeter modules are being constructed for the CEBAF Large Acceptance Spectrometer that will utilize plastic plate scintillators that can be over 4 meters in length. At shower maximum, it is expected that up to 100 Gray may be deposited over a ten year lifetime in the detector elements. Although it is believed that PVT-based scintillators are radiation-hard at that level, the large size of the plates motivated an aging test of a 2 meter long samples so as to gain a realistic estimate of the loss in intrinsic light output and especially in attenuation performance of the chosen scintillator (Bicron BC412). A test setup was designed so that the sample was irradiated (by a ⁶⁰Co line source) at a rate sufficiently low (0.5 Gray/hr) to allow complete diffusion of oxygen into the material during the irradiation. Additionally, in order to ensure complete diffusion and to gain a pessimistic estimate of damage, a pure oxygen atmosphere was circulated through the sample container during the irradiation, and the total dose was increased to a total of 160 Gray. Within the same setup, tests were also made of two additional materials: (1) a 1 meter long sample of an uniquely bright, fast green scintillator with superior attenuation properties, and (2) a customized acrylic scintillator (with a high doping level of fluors) read out by embedded (into smooth grooves cut into the surface of the scintillator) wavelength shifting fibers doped with the same green fluor as the aforementioned scintillator. The data indicates that the BC412 shows no loss in intrinsic light output, but does have an attenuation loss amounting to 10% at 1 meter and 16% at 2 meters. The fast green scintillator (and fibers) showed no damage. When read out by WLS fibers, the acrylic scintillator displayed a loss in intrinsic light output, but no change in attenuation

[en] Experimental data on quasielastic electron scattering by carbon nuclei in the reaction (e,e'p) are presented for incident-electron energies of 1.6 and 2.06 GeV, the electron scattering angles being 19.5 degree sign and 14.2 degree sign , respectively. Recoil protons are detected in the momentum range between 420 and 640 MeV/c. Owing to the chosen kinematical conditions, information about the interaction of electrons with a bound proton can be deduced from analysis based on the plane-wave impulse approximation. The results are compared with predictions of theoretical models